Project Summary Anemia is one of the most widespread clinical conditions, affecting over 1.6 billion individuals globally, with the greatest burden among pregnant women and young children. Anemia has been associated with increased risk of adverse health outcomes, including maternal and infant mortality, and impaired cognitive function in children and work capacity in adults. The burden of anemia in India is among the highest in the world, where it exacts a heavy toll in terms of maternal and infant mortality, disability, and lost productivity. Anemia affects an estimated 56% of women of reproductive age, 59% of pregnant women, 63% of lactating women, and 70% of young children in India. Iron deficiency is the leading cause of anemia worldwide, and iron supplementation is the standard of care for prevention and treatment of anemia. However, it is estimated that only approximately 50% of anemia is due to iron deficiency. Other nutritional factors, particularly vitamins B12 and folate, and non-nutritional factors such as inflammation, also contribute to the etiology of anemia and impact human health. Treating anemia with the incorrect micronutrient may exacerbate the condition or mask the true deficiency. Accurate determination of the multifactorial causes of anemia is critical to implement successful interventions; however, existing diagnostic methods for anemia are typically time consuming, expensive, require cold chain, and are not easily accessible in resource-limited settings. In this application, we propose to develop and validate AnemiaPhone, a point-of-care, low-cost, smartphone-based platform for a multiplexed, quantitative assessment of B-vitamin status (vitamin B12 and folate), in addition to iron status, and inflammation, the leading causes of anemia. The technology consists of a disposable test-strip containing reagents required for a multiplex sandwich ELISA, a reusable low-cost smartphone accessory, which accepts the test strip after the finger stick blood sample has been introduced and attaches it to the smartphone, and a smartphone application that extracts images of the test strip captured by the smartphone camera, interprets image data to provide quantitative test results, and communicates and catalogues data. This application directly responds to the call in the funding opportunity announcement for re-engineering of existing medical devices to significantly improve conditions of the poorest populations by providing affordable and accessible healthcare in resource-limited settings. It brings together a team of experts from St. John's Research Institute in India and Cornell University in the United States in diverse areas including nutrition, medicine, perinatal health, infectious disease, nanotechnology, microfluidic technologies, and engineering to target anemia, an urgent public health problem in India and other resource-limited settings. Availability of AnemiaPhone within the next two years will make it possible to reliably and accurately diagnose anemia in even the most remote parts of India with little training required. Furthermore, given the widespread prevalence of anemia, this technology will benefit low-resource settings globally. The impact of this translational research and the development of a point-of-care, low-cost, smartphone-based platform to reduce the adverse health and development consequences associated with anemia in resource-limited settings cannot be overemphasized.